Better/Safer to submit Paper Tax Return rather than Online?

I filed my 15/16 return with no mention of p2p returns as i pay tax on account, in my own mind i would have declared it the year after, however i received a letter from hmrc inviting me to revisit my return, written along the lines of, in their words "we receive information from companies who pay interest at gross rates without tax deducted" 

I contacted hmrc by phone and had a chat with them and explained my position, they then told me their's, 'so i revisited my return' and declared my income from p2p, as far as the calculations are concerned they were all correct as far as could see, 20% tax to pay on the income received.

What i was not too happy about, as stated above, i pay tax on account, and they have automatically assumed that i will receive the same amount of income from p2p next year, and so i have had to pay another lump of tax on 31st July to cover what they perceive i will owe next year.

Come my return in jan 18 i'm hoping for a lump back, or a lump 'off' my tax liability (Thanks to some good advice elsewhere) as my amounts in p2p have dropped by 50% ish, * AND I HAVE A BAD DEBT AT FUNDINGSECURE.

I suppose i could have made an application for a reduction in my next years liability due to my change in circumstances, bet i'm not sure if i need the hassle.

As for your original question, all seemed Ok to me, and all done online, barring the phone call. 

Hope this all makes sense..... tho i doubt it. 

*Edit.

ozboy this thread may be useful

I made an application for a reduction in next year's tax on account because I am expecting a significant reduction in one source of income.  The process was really easy.  It was just one extra question at the end of my online text return.  HMRC accepted my claim without question and reduced my tax on account.

The 'problem' with online HRMC submissions is limited to a few very specific situations.  See link below for the full list.  I think that items 51, 52 and 56 are the ones which will relate to p2p interest.

www.sa2000.co.uk/2017-exc-indi.pdf

The online form calculates your tax BEFORE you actually submit the form.  So, thinking that I may be impacted, I calculated my tax liabaility (or lack of it) before filling in the form. Their calculation was the same as mine, so I hit the button.

I filled in my 16/17 return online yesterday. The only problem was that it dumped me out 7 or 8 times but then was able to get straight back in at the same point I left off.
Apart from P2P issues , I generally like the fact that you can see your tax calculation straightaway, so you can pick up on any errors you might have made. In my experience the calculation is spot on .